I've seen in many lists of OpenWRT devices that most devices are supporting a specific version like 22.03.3 (currently 1st March 2023) or other versions like 21.02.05.
But others are plainly supporting "snapshot". What does "snapshot" mean exactly? Like just a specific snapshot version of the git tracker and no other?
See:
I know what a snapshot means, in fact I have built installed multiple snapshot in several almost non supported routers like WR841 but what I don't really understand why certain routers say "Snapshot" in their version instead of 22.03.3 or 21.02.5 like most do. Because whatever the snapshot is, it must be technically tied to certain version.
For example the famous https://openwrt.org/toh/xiaomi/ax3600
It's a snapshot, but I think its tied to 22.03.3 by the time the snapshot was issued.
Did you review the Wiki page?
Also see:
No. The opposite is true. Numbered versions [release candidates] are branched off at a certain point in the Master Branch (i.e. SNAPSHOT).
See: https://git.openwrt.org/?p=openwrt/openwrt.git;a=heads
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Ok, this is what I understood. I better understand it from a Git view
Snapshot = Master branch build, say a specific commit number
Version (22.03.3) = Snapshot at certain master point, attachment to certain Commit (git version)
This is clear.
But what is not clear for me is the release process. I mean:
For example, lets say a common popular device:
If I build from branch 22.03, the firmware will always build for me for such device. For example Branch 22.03:
But in the previous example:
I must assume that only one snapshot (one exclusive commit) will be working for that device? Or any commits from that commit will work from master?
Second question. From what I've read in the docs
TL;TR: can I assume this is the catch for any single device?
Snapshot = Dev build
XX.YY.Z = Prod build
So following my examples, AX3600 doesn't have a prod build yet while E8450 does.
Can you elaborate - to provide more basis to this inquiry?
???
Maybe this will help:
The ipq807x target just came into existence as I recall, so there is no version 22. I looked in the directory:
https://downloads.openwrt.org/releases/22.03.3/targets/
ipq807x doesn't exist.
I think you're specifically referring to a device with a newly supported target. The Wiki explains (as well as threads) - therefore the first "prod" will likely be the next version.
x.00.0
Where x > 22
Also, feel free to search the official Git to see the exact commit that added target support, added support for your device, etc. 
So basically snapshot for a specific device means that it still without a version, maybe ipq807x will be there for 23.X
I think I was confused because of this kind of snapshot, which I believe, is not the same as the ipq807x snapshot example
Ummmmm no, I would simply say:
"If support came into existence after 22.00.0 was branched off, it only would have SNAPSHOTS available."
Your link looks exactly like a commit that added support for a new device, so I'm not sure how it differs from what's already discussed.
My bad, now I think where is my confusion.
The problem with TL-WR841N is that it was supported from that snapshot (commit) BUT then OpenWRT removed support TO ALL routers with 4/32 AFTER 19.0X. If TL-WR841N had lets say 8/64 it would be supported til now, and probably it would appear in the 22.04 bran list of supported chipsets.
So I must assume that since ipq807x was supported since that commit, this means that it will be 100% in the list of supported chipset for 23.XX, right?
???
Are you saying that you want to find the removal commits???
Have you looked for answers in the Wiki and forum?
There's a lot of history and information on this.
You must?
(My bad, I really don't understand the basis of this inquiry. Perhaps others can respond to it.)
Yes, I read this, but I forgot the "supportability" regards for this topic.
Maybe I shan't must. I "might foresee" is better
But more or less I think that now I understand the whole topic.
I have glanced quickly over what was already discussed and I would like to sum up my understanding:
If the techdata says "snapshot" it means that no stable build is available. So yes, these are the newer devices that were added after 22.03.0 was released. 22.03.0 was branched off of git master from a specific commit. New devices are usually not backported to stable releases.
Meanwhile, development goes on and device support is added to git master. These versions are called snapshots as automated builds are provided, reflecting a snapshot of the current git tree (i.e. head).
I get your point with associating snapshot with a specific commit. However, usually device support is not removed unless there is a technical reason for it, so snapshot means "from now on, support for it is in the git master tree".
Yes, this is what I read from lines.
Still something else I don't really understand about 4/32 devices.
According to this: https://openwrt.org/supported_devices/openwrt_on_432_devices
From 19.07 technically they were tagged as 21.02 "Not likely viable for 4 MB flash devices", so basically all devices with 4/32 were removed from targets at that point. I think this was the only point in OpenWRT where devices were removed from targets, right?
I would use @andyboeh's words:
No need to over think this statement. It covers the 4/32, other issues, etc.
Ok, I've got the whole picture now.
No, complete platforms have been dropped (adm5120, adm8668, ar7, ar71xx, arc770, au1000, cns3xxx ... just to name the first few in alphabetical order from 17.01 to git head).
I got the wrong impression that just some real hardware limitations were the factor (like the fact that a 21.0X firmware weights 5Mb so a 4Mb will not have space to set it). But now I feel that any platform can drop at any point. So there is no LTS equipment 
Kind of a paradox that all my random thought purchases 10+ yr ago like TP-Link 1043NDv1 (the first I found in the shelf) are still "kind" of supported (although terribly with 32 RAM), but I feel that my really deep thought processed purchases could be dropped anytime soon.
Lol use x86_64...
It's supported until 128-bit computing (or quantum processing) comes to consumers...lol
Yeah, still I like to purchase many on a regular basis, mostly for family and friends to act as dumb AP. Given that wireless tech is constantly evolving (for example the support for that 802.11r that I'm currently lacking on "old" 19.07 builds). I've never found a good x86_64 candidate for dumb AP considering all are simply little computers with a Wifi external antenna at best.
Well, compare that to when the manufacturer dropped support for it!?
Have a look at the targets, mostly the number of devices/users: ath79 has a lot of devices, this won't be dropped soon. The same is true for some other Qualcomm and Mediatek targets. However, I'm currently trying to port a cavium-octeon device, there are about 5 other devices supported by OpenWrt. Someone has to maintain the complete target, for just five devices...
